Written by Catharine Paddock PhD
A new brain imaging study led by researchers at Yale University shows how people who regularly practise meditation are able to switch off areas of the brain linked to daydreaming, anxiety, schizophrenia and other psychiatric disorders. The brains of experienced meditators appear to show less activity in an area known as the “default mode network”, which is linked to largely self-centred thinking. The researchers suggest through monitoring and suppressing or “tuning out” the “me” thoughts, meditators develop a new default mode, which is more present-centred.
A report of their findings is due to be published online this week in the Proceedings of the National Academy of Sciences. Meditation can help deal with a variety of health problems, from quitting smoking, to coping withcancer, and even preventing psoriasis, one of the researchers said in a statement. For this study, they wanted to look further into the neurological mechanisms that might be involved.
Lead author Judson A. Brewer, assistant professor of psychiatry at Yale, and colleagues, used fMRI (functional magnetic resonance imaging) scans to observe the brains of both novice and experienced meditators as they practised three different forms of meditation.
They found that the experienced meditators, regardless of the type of meditation they practised, seemed able to switch off the default mode network, which has been linked to lapses of attention, and disorders such as attention deficit and hyperactivity disorder (ADHD), and anxiety. This part of the brain, comprising the medial prefrontal and posterior cingulate cortex, has also been linked to the accumulation of beta amyloid plaques in Alzheimer’s disease.
They also found that when the default mode network was active in the experienced meditators, other parts of the brain, associated with self-monitoring and cognitive control, were active at the same time. This was not the case with the novices. This could be the result of meditators constantly monitoring mind-wandering and the emergence of “me” thoughts, and suppressing them. These are the kind of thoughts, when in extreme or pathological form, are associated with diseases such as autism and schizophrenia.
The fMRI scans showed the experienced meditators’ brain activity was the same both during meditation and when they were just resting, or when they were not being told to do anything in particular. Thus the researchers concluded that perhaps experienced meditators have developed a new default mode, which is centred more on the present than on the self. Meditation has been a central part of philosophical and contemplative practices for thousands of years: it helps the practitioner to be mindful of the present moment, Brewer told the press, and studies have shown it is also linked to increased levels of happiness.
“Conversely, the hallmarks of many forms of mental illness is a preoccupation with one’s own thoughts, a condition meditation seems to affect,” he added. This study appears to have uncovered some clues as to the neural mechanisms that underpin this process. Understanding more about them will hopefully help us investigate a host of diseases, said Brewer.